| Message ID | 20221031015329.141954-6-damien.lemoal@opensource.wdc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v4,1/7] block: Prevent the use of REQ_FUA with read operations | expand |
On 10/31/22 02:53, Damien Le Moal wrote: > If a user issues a write command with the FUA bit set for a device with > NCQ support disabled (that is, the device queue depth was set to 1), the > LBA 48 command WRITE DMA FUA EXT must be used. However, > ata_build_rw_tf() ignores this and first tests if LBA 28 can be used > based on the write command sector and number of blocks. That is, for > small FUA writes at low LBAs, ata_rwcmd_protocol() will cause the write > to fail. > > Fix this by preventing the use of LBA 28 for any FUA write request. > > Given that the WRITE MULTI FUA EXT command is marked as obsolete iin the > ATA specification since ACS-3 (published in 2013), remove the > ATA_CMD_WRITE_MULTI_FUA_EXT command from the ata_rw_cmds array. > > Finally, since the block layer should never issue a FUA read > request, warn in ata_build_rw_tf() if we see such request. > > Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> > --- > drivers/ata/libata-core.c | 12 +++++++++--- > 1 file changed, 9 insertions(+), 3 deletions(-) > Reviewed-by: Hannes Reinecke <hare@suse.de> Cheers, Hannes
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 30adae16efff..83bea8591b08 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -552,7 +552,7 @@ static const u8 ata_rw_cmds[] = { 0, 0, 0, - ATA_CMD_WRITE_MULTI_FUA_EXT, + 0, /* pio */ ATA_CMD_PIO_READ, ATA_CMD_PIO_WRITE, @@ -693,6 +693,10 @@ int ata_build_rw_tf(struct ata_queued_cmd *qc, u64 block, u32 n_block, tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE; tf->flags |= tf_flags; + /* We should never get a FUA read */ + WARN_ON_ONCE((tf->flags & ATA_TFLAG_FUA) && + !(tf->flags & ATA_TFLAG_WRITE)); + if (ata_ncq_enabled(dev)) { /* yay, NCQ */ if (!lba_48_ok(block, n_block)) @@ -727,7 +731,8 @@ int ata_build_rw_tf(struct ata_queued_cmd *qc, u64 block, u32 n_block, } else if (dev->flags & ATA_DFLAG_LBA) { tf->flags |= ATA_TFLAG_LBA; - if (lba_28_ok(block, n_block)) { + /* We need LBA48 for FUA writes */ + if (!(tf->flags & ATA_TFLAG_FUA) && lba_28_ok(block, n_block)) { /* use LBA28 */ tf->device |= (block >> 24) & 0xf; } else if (lba_48_ok(block, n_block)) { @@ -742,9 +747,10 @@ int ata_build_rw_tf(struct ata_queued_cmd *qc, u64 block, u32 n_block, tf->hob_lbah = (block >> 40) & 0xff; tf->hob_lbam = (block >> 32) & 0xff; tf->hob_lbal = (block >> 24) & 0xff; - } else + } else { /* request too large even for LBA48 */ return -ERANGE; + } if (unlikely(!ata_set_rwcmd_protocol(dev, tf))) return -EINVAL;
If a user issues a write command with the FUA bit set for a device with NCQ support disabled (that is, the device queue depth was set to 1), the LBA 48 command WRITE DMA FUA EXT must be used. However, ata_build_rw_tf() ignores this and first tests if LBA 28 can be used based on the write command sector and number of blocks. That is, for small FUA writes at low LBAs, ata_rwcmd_protocol() will cause the write to fail. Fix this by preventing the use of LBA 28 for any FUA write request. Given that the WRITE MULTI FUA EXT command is marked as obsolete iin the ATA specification since ACS-3 (published in 2013), remove the ATA_CMD_WRITE_MULTI_FUA_EXT command from the ata_rw_cmds array. Finally, since the block layer should never issue a FUA read request, warn in ata_build_rw_tf() if we see such request. Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> --- drivers/ata/libata-core.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)